By Rachel Ewing
Hurricane Sandy landed right on top of Dr. Tracy Quirk’s wetland monitoring stations–but it wasn’t all bad news.
Quirk, an Academy scientist and assistant professor in the Department of Biodiversity, Earth and Environmental Science at Drexel University, had been performing wetland research for several years at monitoring sites in Barnegat and Delaware Bays in New Jersey. Recording devices installed at these sites continuously measured water level and salinity for a wide range of wetland studies at the Academy and Drexel.
As Sandy hit and water levels rose, those measurements continued.
“We have continuous data on how long these areas were flooded and how high the water rose at these sites,” said Quirk.
It was a stroke of good luck to have captured detailed measurements during a storm of this rare magnitude. Quirk recognized that the data could provide new answers to the questions she had been investigating about how wetland ecosystems sustain themselves and function. Now she could also learn how marshes responded to the severe disturbance effect of the storm.
“The prospect of future storms of this magnitude suggests that we will need to understand their effects on ecosystem dynamics as part of the ‘new normal,’” Quirk said.
In February she began working on an intensive year-long project, funded by the National Science Foundation, to evaluate ecosystem processes in New Jersey’s salt marshes before, during, and for a year following Hurricane Sandy. Quirk is beginning to analyze findings from the study now.
There was some good news from the marshes: Although some water-level recorders were over-topped and stopped recording (making it difficult to use direct measures of the water height), there was evidence of marsh swelling during the storm.
That swelling is an indication of marshes’ ability to absorb some of the storm surge–which, in hard-hit urban areas, had resulted in high water marks up to seven feet during Hurricane Sandy. Quirk points out that resilient, healthy wetlands near coastal areas have a key role in protecting local communities from hurricane-induced storm surges and flooding.
“Imagine having a marsh in front of your house instead of concrete,” Quirk said. “Paved areas make flooding worse because water has nowhere to go.”
In her post-Sandy research, Quirk was interested in finding out whether the storm affected how the marshes sustain themselves. The disturbance of an intense storm could alter the delicate equilibrium between flooding, vegetation growth and sediment deposits in wetland ecosystems – either temporarily or long-term.
That’s where the bad news comes in. As she works through the data analysis this fall, Quirk said she hasn’t found much sign of sediment deposits, before or after the hurricane struck. Sandy had the potential to deposit a lot of sediments, fast, which would have been good for building up wetlands.
Any number of reasons could explain why those hoped-for sediment deposits didn’t materialize, she said. Whatever the reason, Quirk’s findings point to cause for continued concern over the coastal marshes’ future.
To read more about Tracy Quirk’s N.J. coastal wetlands research, check out the press release on the subject.